Further More proving its mastery of chronographs and exclusively high-frequency precision, ZENITH unveils the DEFY El Primero 21 which has a new El Primero calibre beating at a phenomenal level of 50Hz for an exact one/a centesimal of the next chronograph function. Complication: Refers to any enjoy movement past The https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/